How Do I Convert VHS to Digital Video?

Digital video is the use of video capture devices such as video cameras to convert the color and brightness information of external images into electrical signals, and then record them on storage media (such as video tapes).

Digital video

Digital video is the use of video capture devices such as video cameras to convert the color and brightness information of external images into electrical signals, and then record

Digital video is the video recorded in digital form, as opposed to analog video. Digital video has different generation methods, storage methods and broadcast methods. For example, digital video signals are directly generated by digital cameras and stored in digital bands.

When it comes to the development history of digital video, we must not only review the development history of computers, it is actually closely related to the types of information that computers can process. Since the birth of computers in the 1940s, computers have experienced the following developments: stage:

According to the characteristics of the television signal, the bandwidth of the luminance signal is chrominance

For PAL, NTSC and SECAM

Usually used

The goal of video compression is to reduce the video while ensuring the visual effect as much as possible.

MPEG-1 Digital video MPEG-1

The encoding of digital moving media and its accompanying sound for digital storage media with a transmission rate of 1.5 Mbps. After MPEG-1 compression, the video data compression rate is 1 / 100-1 / 2 00, and the audio compression rate is 1 / 6.5 . MPEG-1 provides 30 frames per second with a resolution of 352 * 240. When using the appropriate compression technology, it has a quality close to that of a home video system (VHS) video tape. MPEG-1 allows more than 70 minutes of high-quality video and audio to be stored on a single CD-ROM disc. VCD uses the MPEG-1 standard, which is a video and audio compression standard for home TV quality.

MPEG-2 Digital video MPEG-2

Mainly for the needs of high-definition television (HDTV), the transmission rate is 10Mbps, compatible with MPEG-1, suitable for encoding range of 1.5-60Mbps or higher. MPEG-2 has a resolution of 704 * 480 at 30 frames per second, which is four times the playback speed of MPEG-1. It is suitable for demanding broadcast and entertainment applications such as DSS satellite radio and DVD. MPEG-2 is twice the resolution of home video system (VHS) video tapes.

DAC Digital video DAC

It is a digital / analog converter, a device that converts digital signals into analog signals. The higher the number of DAC bits, the smaller the signal distortion. The image is also sharper and more stable.

AVI Digital Video AVI

AVI is a file format that synchronizes audio and video. It uses a lossy compression method for video files, but the compression is high, so although the quality is not very good, its application range is still very wide. AVI supports 256 colors and RLE compression. AVI information is mainly used on multimedia discs to save various video information such as TV and movies.

RGB Digital video RGB

The method of encoding a color is collectively called "color space" or "color gamut". "Color space" can be defined as a fixed number or variable. RGB (red, green, blue) is just one of many color spaces. With this coding method, each color can be represented by three variables-the intensity of red green and blue. When recording and displaying color images, R GB is the most common solution. However, it lacked good compatibility with early black and white display systems. Therefore, the common practice adopted by many electronic and electrical manufacturers is to convert RGB to YUV color space to maintain compatibility, and then switch back to RGB format as needed to display color graphics on computer monitors.

YUV Digital Video YUV

YUV (also known as YCrCb) is a color coding method (belonging to PAL) adopted by the European television system. YUV is mainly used to optimize the transmission of color video signals, making it backward compatible with older black and white TVs. Compared with R GB video signal transmission, its biggest advantage is that it only takes up very little bandwidth (RGB requires three independent video signals to be transmitted simultaneously). Among them, "Y" represents the brightness (Luminance or Luma), which is the grayscale value; and "U" and "V" represent the chrominance (Chrominance or Chroma), which is used to describe the color and saturation of the image. The color of the specified pixel. Created by the R GB input signal by superposing specific parts of the RGB signal together. "Chroma" defines two aspects of color-hue and saturation, which are represented by Cr and CB, respectively. Among them, C r reflects the difference between the red part of the GB input signal and the brightness value of the RGB signal. The CB reflects the difference between the blue part of the RGB input signal and the brightness value of the RGB signal.

SV Digital Video Video and SV

NTSC and PAL color video signals are constructed in this way-first there is a basic black and white video signal, then after each horizontal sync pulse, a color pulse and a brightness signal are added. Because the color signal is "superimposed" by a variety of data, it is called "composite video." S-Video is a video interface with higher signal quality. It eliminates the signal superposition method, which can effectively avoid some unnecessary quality loss. Its function is to separate the RGB three primary colors and brightness.

NTSCPALSECAM Digital video NTSC, PAL and SECAM

Baseband video is a simple analog signal, consisting of video analog data and video synchronization data, used to correctly display images at the receiving end. The details of the signal depend on the applied video standard or "standard"-NTSC (National Television Standards Committee), PAL (Phase Alternate Line), and SECAM (Sequential Transmission and Storage Color TV System) , A television system adopted in France, SEquential Couleur Avec Memoire). In the PC field, there are incompatibilities due to different standards used. In terms of resolution, some systems have 625 lines (50 Hz) per frame, and some have only 525 lines (60 Hz) per frame. The latter is the standard adopted in North America and Japan, collectively referred to as NTSC. Usually, a video signal is generated by a video source, such as a video camera, VCR, or TV tuner. To transmit an image, the video source first generates a vertical synchronization signal (V SYNC). This signal resets the receiving device (PC monitor), ensuring that the new image is displayed from the top of the screen. After issuing the VSYNC signal, the video source then scans the first line of the image. After completion, the video source generates a horizontal synchronization signal and resets the receiver so that the next line is displayed starting from the left side of the screen. For each line of the image, a scan line and a horizontal synchronization pulse signal are issued.

In addition, the NTSC standard specifies that video sources need to send 30 complete images (frames) per second. If nothing else is done, flicker will be very serious. To solve this problem, each frame is divided into two parts, each with 2 62.5 lines. One part is all odd lines and the other part is even lines. When displaying, scanning the odd lines first and then the even lines can effectively improve the stability of the image display and reduce flicker. SECAM system, the three systems can not be unified. China uses the PAL-D system.

Ultrascale Digital Video Ultrascale

Ultra6cale is a scan conversion technology used by Rockwell. You can zoom the display vertically and horizontally. When displaying progressive video on an interlaced device such as a TV, the entire process itself is very cumbersome. And with UltraScale technology, it can even flex freely in the vertical and horizontal directions like that on a computer monitor.